Year Number of 1990 301.59 1991 309.26 1992 320.23 1993 329.16 1994 342.29 1995 348.98 1996 355.82 1997 362.05 1998 370.08 1999 381.41 2000 388.71 2001 401.97 2002 417.4 2003 435.84 2004 456.49 2005 479.75 2006 497.02 2007 514.43 2008 536.42 2009 560.52 2010 589.59 2011 616.12 2012 646.94 2013 679.18 2014 709.93 2015 745.01 2016 781.48